Can you say me where are this functions?
those would be the ones accessible through iGraphics2D interface
It could be that you need to restart the application for those change to be really effective.
In that case, you'll want to update/set one or more of these configuration key-value pairs in your application configuration file:
Video.ScreenWidth = 800
Video.ScreenHeight = 600
Video.FullScreen = no
Easy application restart is a feature of csApplicationFramework; to change config files, you can/should use csConfigAccess, problably like it's used in CS/apps/tutorial/simpvs/simpvs.cpp